Protesters angered by high food prices flooded the streets of Haiti's capital Monday, forcing businesses and schools to close as unrest spread from the countryside.

Witnesses said at least one person was killed by hotel security guards during a protest in the southern city of Les Cayes, where at least four people died last week in food riots and clashes with U.N. peacekeepers. Police said they were investigating.

Thousands of people marched mostly peacefully past the National Palace in Port-au-Prince. "We're hungry," some called out. Others carried posters reading "Down with the expensive life!"

Some protesters threw chairs against buildings and shouted for the U.N. troops to leave the country, blaming them for the high price of rice.

A U.N. spokeswoman appealed for calm as peacekeepers defended government buildings.

"We call on the population to reject the trap of violence. Violence will just make the cost of living worse," Sophie Boutaud de la Combe said.

Haitians are particularly affected by food prices that are rising worldwide. Eighty percent of the population lives on less than US$2 (euro1.27) a day. The cost of staples such as rice, beans, fruit and condensed milk has gone up 50 percent in the past year, while the cost of pasta has doubled.

"Some can't take the hunger anymore," the Rev. Gerard Jean-Juste told The Associated Press. "As a priest, I encourage all government officials to do their best to find ways to solve the near-famine situation."

The U.N. World Food Program made an urgent appeal for donations Monday to support its operations in Haiti, the poorest nation in the Western Hemisphere. U.N. Secretary-General Ban Ki-moon warned last week that the food crisis could threaten Haiti's already fragile security.